How to Troubleshoot a Millivolt Gas Stove Thermostat

Although all gas ovens use gas as the heat source, they do not all operate the same. Specifically, not all gas ovens use the same type of ignition system. Some gas ovens use a pilot ignition system that depends on a thermostat to tell the system when to heat the stove. In a pilot ignition system, both a thermocouple and thermopile are used. The thermopile powers a second circuit that is used to power the thermostat. The actual pilot light in a pilot light ignition system stays lit at all times. When the thermostat is turned on, the pilot's flame gets bigger, which, in turn, creates the chain reaction necessary to heat the oven. If your stove's thermostat is not operating correctly, it can be the cause of your stove not heating properly or not heating at all.

Things You'll Need

Voltmeter

Small wire

Inspect the pilot flame when you turn the thermostat on. If the flame does not visually increase, or extend, when the thermostat is turned on, the thermostat may be defective and need to be replaced.

Check the millivolts on the thermopile with a voltmeter. Your owner's manual should contain the proper readings. If it needs adjustment, you can adjust it with the pilot adjustment screw. The thermopile is typically located next to the pilot hood (see Resources).

Check the electrical connection to the thermostat by using a small wire to "jump" it. Connect the wires from the terminals on the "TH" and "TP," or thermocouple and thermopile, valves. If the stove turns on when the connection is jumped, then your problem likely lies farther down the electrical circuit and is not your thermostat.

Tips & Warnings

Use extreme caution when inspecting or repairing a gas appliance as gas is highly combustible and can ignite or explode.